1. Technical Field
The present disclosure relates to heat dissipation, and more particularly to a heat sink assembly including a wire clip.
2. Description of Related Art
Heat produced during operation of electronic components such as central processing units (CPUs) must be quickly removed to allow the electronic components to function normally. Often, a heat sink is disposed on an electronic component mounted on a printed circuit board to dissipate heat therefrom.
Wire clips are frequently used to secure heat sinks onto printed circuit boards. Referring to FIG. 1, a commonly used heat sink assembly 10 includes a heat sink 11 and a wire clip 15. The heat sink 11 includes a base 12, and a plurality of fins 13 extending from the base 12. The wire clip 15 includes a central contact portion 17 defining a major axis, and a pair of elastic portions 18 extending from opposite ends of the contact portion 17. As viewed from a side of the wire clip 15 along a direction of the major axis (FIG. 2), one of the elastic portions 18 extends generally toward a left of the contact portion 17, and the other elastic portion 18 extends generally toward a right of the contact portion 17. Thus the two elastic portions 18 together with the contact portion 17 define a substantially V-shaped device. The contact portion 17 is received between two adjacent central fins 13 of the heat sink 11, and the elastic portions 18 hook the printed circuit board. The contact portion 17 includes a central protruding section 19, which is offset from and parallel to other sections of the contact portion 17. The protruding section 19 limits rotation of the contact portion 17 relative to the heat sink 11.
Referring to FIG. 2, since the contact portion 17 with the protruding section 19 is blocked and held in position in the heat sink 11, values of hooking forces of the elastic portions 18 are proportional to angles defined between the elastic portions 18 and the protruding section 19. However, due to ordinary manufacturing imprecision (i.e., tolerances), when the wire clip 15 is in an original relaxed position, an angle A1 between one elastic portion 18 and the protruding section 19 may differ from an angle B1 between the other elastic portion 18 and the protruding section 19. Thus when the elastic portions 18 are moved to horizontal positions and are hooked to the printed circuit board in locked positions, a variable angle A2 between said one elastic portion 18 at the original relaxed position and said one elastic portion 18 at the locked position is liable to be different from a variable angle B2 between the other elastic portion 18 at the original relaxed position and the other elastic portion 18 at the locked position. When this happens, the values of the hooking forces of the elastic portions 18 are imbalanced, and the heat sink 11 is liable to be unstably mounted.
What is needed, therefore, is a heat sink assembly having a heat sink and a clip, wherein the clip can firmly and evenly secure the heat sink to a printed circuit board.